I want to add a Mobius Strip (figure of 8) through this model I've built

I have no Photoshop experience so this is just a rubbish quick example I did. I built a model of the Mobius House which is based on a never ending loop. I want this figure of 8 to blend from one colour to the next, like in my example, but I'm so lost how to do it without using a freehand brush which obviously looks rubbish. The idea is that the blue rooms are the bedrooms, then they go downstairs to the red (far left), goes underneath the blue bedrooms and still out red the other side (right), and then through the yellow. It is meant to reflect a path through day to night.

Link to original file without my example over it (hope this works)

https://www.dropbox.com/s/ksq9267syz1tz03/model.psd?dl=0

Thank you so much if anyone can help

/r/PhotoshopRequest Thread Link - i.redd.it